Uma proposta didática para o ensino médio sobre serviços ecossistêmicos no controle de insetos

Abstract

Insects account for about 54% of all known species and are important in pollination, nutrient cycling and biological pest control. Some species are considered harmful because they transmit diseases to humans and animals or because they attack plants or their products, causing significant damage to the economy. When studying Ecology in secondary education, more specifically the structure of ecosystems, knowing the dynamics of insect species, which establish interactions with agricultural plants, and of their natural predators, helps the student to understand the importance of these animals and adopt measures to preserve ecosystems and agroecosystems. Thus, this study aimed to analyze a didactic proposal focused on the teaching of elements of Ecology, in Biology, through activities involving the study of ecosystem services provided by insects and other agents in the control of pests in subsistence crops. The proposal was applied to students in the 2nd grade of secondary education of a state school in the municipality of Bananeiras, Paraíba State, Brazil. Expository-dialog classes and a directed study were conducted to motivate and prepare the students for practical classes, aimed at catching insects. The insects were captured in crops of corn, fava bean, beans, sweet potatoes, cassava, okra and vegetables. The captured animals were killed by thorax compression or by immersion in alcohol (70%); then the specimens were dehydrated, pinned, classified, labeled and accommodated in an entomological box, in which they were grouped according to dietary habits. Thus, four groups were obtained: predators, parasitoids, pests and pollinators. In the final stage, the students asked a series of questions and the answers were used to develop a manual. The results were evaluated based on the products generated by the students, such as report, manual, video and entomological collection, among others, in addition to more subjective elements, such as participation in activities, motivation and interaction with the teacher, among students and with the approached subject. Thus, students’ active participation was observed in the search for knowledge related to morphological, ecological and economic aspects. The way the activities were conducted and the results obtained allow us to conclude that the method contributed effectively to the students’ learning about the general characteristics of insects and about their role in the ecosystems as well as to understand it is necessary to preserve these animals so that we can continue to enjoy their benefits.